Monitors are such a subjective thing... However, if you get a chance to hear them, do it. They've (the Diamond series, specifically) been racking up 5-star ratings in the U.K. for years.
Keep in mind that these are Hi-Fi loudspeakers - Although I've mixed through them, and prefer mixing through them as opposed to the Mack's, or most speakers for that matter (I used to bring them along to every studio I went to for tracking or mixing), they probably aren't everyone's cup of tea. However, if you're looking for "real-world" speakers with great imaging, you've got to try them.
And again, no idea on the active series. I can only assume that they sound different with all that mass in the cabinet. However they (Wharfedale contacted me directly on this), tell me that they're pretty faithful to sound of the original Diamonds.